/* ==========================================================================
   谷歌浏览器手机版下载 - 全局样式
   ========================================================================== */
:root {
  --blue: #4285F4;
  --red: #EA4335;
  --yellow: #FBBC05;
  --green: #34A853;
  --text: #202124;
  --text-secondary: #5f6368;
  --border: #dadce0;
  --bg: #ffffff;
  --bg-alt: #f8f9fa;
  --shadow-sm: 0 1px 3px rgba(60, 64, 67, 0.15);
  --shadow-md: 0 4px 12px rgba(60, 64, 67, 0.18);
  --shadow-lg: 0 12px 32px rgba(60, 64, 67, 0.2);
  --radius: 16px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Roboto", "PingFang SC", "Microsoft YaHei", "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 20px;
}

.container-narrow {
  max-width: 760px;
}

a {
  color: var(--blue);
  text-decoration: none;
}

img, svg {
  vertical-align: middle;
}

/* ==========================================================================
   顶部导航
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: 0.2px;
}

.brand-logo {
  width: 30px;
  height: 30px;
  filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.12));
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-link {
  color: var(--text);
  font-size: 0.95rem;
  font-weight: 500;
  position: relative;
  padding: 6px 0;
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background: var(--blue);
  border-radius: 2px;
  transition: width 0.25s ease;
}

.nav-link:hover::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 8px;
  background: transparent;
  border: none;
  cursor: pointer;
  border-radius: 8px;
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 2.5px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-toggle.open span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

/* ==========================================================================
   按钮
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 999px;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.2s ease, background 0.2s ease;
  letter-spacing: 0.3px;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--blue);
  color: #fff;
  box-shadow: 0 2px 6px rgba(66, 133, 244, 0.4);
}

.btn-primary:hover {
  background: #3367d6;
  box-shadow: 0 4px 12px rgba(66, 133, 244, 0.45);
}

.btn-ghost {
  background: transparent;
  color: var(--blue);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  background: rgba(66, 133, 244, 0.08);
}

.btn-lg {
  padding: 16px 44px;
  font-size: 1.1rem;
}

.btn-block {
  width: 100%;
}

/* ==========================================================================
   Hero 主视觉区
   ========================================================================== */
.hero {
  background: linear-gradient(180deg, #f0f5ff 0%, #ffffff 60%);
  overflow: hidden;
  padding: 56px 0 72px;
}

.hero-inner {
  display: flex;
  align-items: center;
  gap: 56px;
}

.hero-text {
  flex: 1;
}

.hero-text h1 {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.hero-text h1 em {
  font-style: normal;
  background: linear-gradient(90deg, var(--blue), var(--red), var(--yellow), var(--green));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-sub {
  margin-top: 18px;
  font-size: 1.1rem;
  color: var(--text-secondary);
}

.hero-actions {
  display: flex;
  gap: 14px;
  margin-top: 30px;
  flex-wrap: wrap;
}

.hero-note {
  margin-top: 18px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* Hero 手机展示 */
.hero-visual {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  min-height: 420px;
}

.phone-frame {
  position: relative;
  width: 210px;
  height: 420px;
  background: #111;
  border-radius: 38px;
  padding: 10px;
  box-shadow: var(--shadow-lg), inset 0 0 0 2px #333;
  z-index: 2;
  animation: float 5s ease-in-out infinite;
}

.phone-notch {
  position: absolute;
  top: 22px;
  left: 50%;
  transform: translateX(-50%);
  width: 90px;
  height: 22px;
  background: #111;
  border-radius: 12px;
  z-index: 3;
}

.phone-screen {
  width: 100%;
  height: 100%;
  background: linear-gradient(160deg, #e8f0fe, #ffffff);
  border-radius: 30px;
  overflow: hidden;
  padding-top: 52px;
}

.mini-url-bar {
  display: flex;
  align-items: center;
  gap: 6px;
  background: #fff;
  border-radius: 999px;
  margin: 0 12px 14px;
  padding: 8px 12px;
  box-shadow: var(--shadow-sm);
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.mini-lock {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  background: var(--green);
  position: relative;
  flex-shrink: 0;
}

.mini-lock::after {
  content: "";
  position: absolute;
  top: -6px;
  left: 2px;
  width: 6px;
  height: 6px;
  border: 2px solid var(--green);
  border-bottom: none;
  border-radius: 4px 4px 0 0;
}

.mini-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  padding: 6px 14px;
}

.mini-grid i {
  aspect-ratio: 1;
  border-radius: 12px;
  background: #fff;
  box-shadow: var(--shadow-sm);
}

.mini-grid i:nth-child(1) { background: #4285F4; }
.mini-grid i:nth-child(2) { background: #34A853; }
.mini-grid i:nth-child(3) { background: #FBBC05; }
.mini-grid i:nth-child(4) { background: #EA4335; }
.mini-grid i:nth-child(5) { background: #f1f3f4; }
.mini-grid i:nth-child(6) { background: #f1f3f4; }
.mini-grid i:nth-child(7) { background: #f1f3f4; }
.mini-grid i:nth-child(8) { background: #f1f3f4; }

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-14px); }
}

/* Chrome 三色环装饰 */
.chrome-ring {
  position: absolute;
  width: 130px;
  height: 130px;
  border-radius: 50%;
  border: 26px solid var(--blue);
  filter: blur(1px);
  opacity: 0.9;
  z-index: 1;
}

.chrome-ring-1 {
  top: 6%;
  left: 8%;
  animation: spin-slow 18s linear infinite;
  border-top-color: var(--blue);
  border-right-color: var(--green);
  border-bottom-color: var(--green);
  border-left-color: var(--blue);
}

.chrome-ring-2 {
  bottom: 8%;
  right: 6%;
  width: 90px;
  height: 90px;
  border-width: 18px;
  animation: spin-slow 14s linear infinite reverse;
  border-top-color: var(--red);
  border-right-color: var(--yellow);
  border-bottom-color: var(--yellow);
  border-left-color: var(--red);
}

.chrome-ring-3 {
  top: 42%;
  right: 20%;
  width: 60px;
  height: 60px;
  border-width: 12px;
  animation: spin-slow 10s linear infinite;
  border-top-color: var(--yellow);
  border-right-color: var(--blue);
  border-bottom-color: var(--blue);
  border-left-color: var(--yellow);
}

@keyframes spin-slow {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* ==========================================================================
   通用区块
   ========================================================================== */
.section {
  padding: 72px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-head {
  text-align: center;
  margin-bottom: 44px;
}

.section-head h2 {
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
  font-weight: 700;
  letter-spacing: 0.3px;
}

.section-head p {
  margin-top: 8px;
  color: var(--text-secondary);
}

/* ==========================================================================
   下载区
   ========================================================================== */
.download-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
  max-width: 880px;
  margin: 0 auto;
}

.download-card {
  position: relative;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 30px;
  text-align: center;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.download-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
}

.download-card.featured {
  border: 2px solid var(--blue);
  box-shadow: 0 8px 24px rgba(66, 133, 244, 0.15);
}

.featured-tag {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--blue);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 600;
  padding: 4px 16px;
  border-radius: 999px;
  white-space: nowrap;
}

.card-icon {
  width: 72px;
  height: 72px;
  margin: 0 auto 18px;
  border-radius: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 14px;
}

.card-icon svg {
  width: 100%;
  height: 100%;
  fill: #fff;
}

.and-icon {
  background: linear-gradient(135deg, #34A853, #188038);
  box-shadow: 0 4px 12px rgba(52, 168, 83, 0.35);
}

.ios-icon {
  background: linear-gradient(135deg, #4285F4, #1a56c4);
  box-shadow: 0 4px 12px rgba(66, 133, 244, 0.35);
}

.download-card h3 {
  font-size: 1.35rem;
  margin-bottom: 10px;
}

.card-desc {
  color: var(--text-secondary);
  font-size: 0.92rem;
  min-height: 44px;
}

.card-points {
  list-style: none;
  text-align: left;
  margin: 18px 0;
  display: grid;
  gap: 8px;
}

.card-points li {
  position: relative;
  padding-left: 26px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.card-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--green);
  -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M9 16.2 4.8 12l-1.4 1.4L9 19 21 7l-1.4-1.4z'/%3E%3C/svg%3E") center/contain no-repeat;
  mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M9 16.2 4.8 12l-1.4 1.4L9 19 21 7l-1.4-1.4z'/%3E%3C/svg%3E") center/contain no-repeat;
}

.version-row {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.version-tag {
  font-size: 0.78rem;
  color: var(--text-secondary);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  padding: 3px 10px;
  border-radius: 999px;
}

.download-tip {
  max-width: 760px;
  margin: 36px auto 0;
  display: flex;
  align-items: flex-start;
  gap: 12px;
  background: #fef7e0;
  border: 1px solid #f9e7b3;
  border-radius: 12px;
  padding: 14px 18px;
}

.download-tip svg {
  width: 20px;
  height: 20px;
  fill: #b06000;
  flex-shrink: 0;
  margin-top: 3px;
}

.download-tip p {
  font-size: 0.88rem;
  color: #8f5a00;
}

/* ==========================================================================
   功能特性
   ========================================================================== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px 26px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 12px;
  background: linear-gradient(135deg, var(--blue), var(--green));
  margin-bottom: 16px;
}

.feature-icon svg {
  width: 100%;
  height: 100%;
  fill: #fff;
}

.feature-card:nth-child(2) .feature-icon { background: linear-gradient(135deg, var(--green), #0b6e3a); }
.feature-card:nth-child(3) .feature-icon { background: linear-gradient(135deg, var(--red), #c5221f); }
.feature-card:nth-child(4) .feature-icon { background: linear-gradient(135deg, var(--yellow), #f9ab00); }
.feature-card:nth-child(5) .feature-icon { background: linear-gradient(135deg, #5f6368, #3c4043); }
.feature-card:nth-child(6) .feature-icon { background: linear-gradient(135deg, #4285F4, #1a56c4); }

.feature-card h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.92rem;
}

/* ==========================================================================
   常见问题
   ========================================================================== */
.faq-list {
  display: grid;
  gap: 14px;
}

.faq-item {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 4px 20px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.faq-item[open] {
  border-color: var(--blue);
  box-shadow: var(--shadow-sm);
}

.faq-item summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  padding: 16px 0;
  list-style: none;
  position: relative;
  padding-right: 32px;
  user-select: none;
}

.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 4px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.5rem;
  color: var(--blue);
  transition: transform 0.25s ease;
  line-height: 1;
}

.faq-item[open] summary::after {
  transform: translateY(-50%) rotate(45deg);
}

.faq-item p {
  padding: 0 0 18px;
  color: var(--text-secondary);
  font-size: 0.94rem;
}

/* ==========================================================================
   底部行动号召
   ========================================================================== */
.cta {
  background: linear-gradient(120deg, var(--blue), #1a56c4);
  color: #fff;
  text-align: center;
  padding: 64px 0;
}

.cta h2 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin-bottom: 10px;
}

.cta p {
  opacity: 0.9;
  margin-bottom: 26px;
}

.cta .btn-primary {
  background: #fff;
  color: var(--blue);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

.cta .btn-primary:hover {
  background: #f1f3f4;
}

/* ==========================================================================
   页脚
   ========================================================================== */
.site-footer {
  background: #202124;
  color: #9aa0a6;
  padding: 40px 0 28px;
  font-size: 0.88rem;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  padding-bottom: 24px;
  border-bottom: 1px solid #3c4043;
  flex-wrap: wrap;
}

.footer-top .brand {
  color: #fff;
}

.footer-links {
  display: flex;
  gap: 22px;
  flex-wrap: wrap;
}

.footer-links a {
  color: #9aa0a6;
}

.footer-links a:hover {
  color: #fff;
}

.footer-bottom {
  padding-top: 20px;
  text-align: center;
  display: grid;
  gap: 4px;
}

/* ==========================================================================
   404 页面
   ========================================================================== */
.error-body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.error-main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 60px 20px;
}

.error-section {
  text-align: center;
  max-width: 640px;
  width: 100%;
}

.error-art {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  margin-bottom: 34px;
}

.error-num {
  font-size: clamp(5rem, 20vw, 8.5rem);
  font-weight: 700;
  line-height: 1;
  background: linear-gradient(135deg, var(--blue), var(--red));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 4px 12px rgba(66, 133, 244, 0.2));
}

.error-globe {
  width: clamp(120px, 22vw, 190px);
  height: auto;
  animation: float 5s ease-in-out infinite;
}

.globe-ring {
  fill: none;
  stroke: var(--green);
  stroke-width: 4;
  opacity: 0.35;
}

.globe-horizon {
  fill: none;
  stroke: var(--blue);
  stroke-width: 4;
}

.globe-band {
  fill: none;
  stroke: var(--yellow);
  stroke-width: 4;
  opacity: 0.6;
}

.globe-dot {
  fill: var(--red);
}

.error-title {
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  font-weight: 700;
  margin-bottom: 12px;
}

.error-desc {
  color: var(--text-secondary);
  font-size: 1.05rem;
  margin-bottom: 28px;
}

.error-actions {
  display: flex;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 26px;
}

.error-code {
  font-family: "Consolas", "Courier New", monospace;
  font-size: 0.82rem;
  color: var(--text-secondary);
  background: var(--bg-alt);
  display: inline-block;
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid var(--border);
}

/* ==========================================================================
   响应式
   ========================================================================== */
@media (max-width: 900px) {
  .hero-inner {
    flex-direction: column-reverse;
    gap: 40px;
    text-align: center;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-visual {
    min-height: 340px;
  }

  .phone-frame {
    width: 170px;
    height: 340px;
  }

  .chrome-ring-1 {
    width: 100px;
    height: 100px;
    border-width: 20px;
    left: 0;
  }

  .chrome-ring-2 {
    right: 0;
  }
}

@media (max-width: 640px) {
  .header-inner {
    height: 58px;
  }

  .nav-toggle {
    display: flex;
  }

  .main-nav {
    position: absolute;
    top: 58px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-md);
    padding: 0 20px;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 0.35s ease, opacity 0.3s ease, padding 0.3s ease;
  }

  .main-nav.open {
    max-height: 320px;
    opacity: 1;
    padding: 12px 20px;
  }

  .nav-link {
    padding: 14px 0;
    border-bottom: 1px solid #f1f3f4;
  }

  .nav-link:last-child {
    border-bottom: none;
  }

  .section {
    padding: 52px 0;
  }

  .hero {
    padding: 40px 0 56px;
  }

  .hero-text h1 {
    font-size: 2rem;
  }

  .download-card {
    padding: 30px 22px;
  }

  .error-art {
    gap: 10px;
  }

  .footer-top {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-links {
    gap: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  html {
    scroll-behavior: auto;
  }
}